Source : Webster's Revised Unabridged Dictionary (1913)

Incendiary \In*cen"di*a*ry\ (?; 277), n.; pl. {Incendiaries}.
   [L. incendiarius: cf. F. incendiaire. See {Incense} to
   inflame.]
   1. Any person who maliciously sets fire to a building or
      other valuable or other valuable property.

   2. A person who excites or inflames factions, and promotes
      quarrels or sedition; an agitator; an exciter.

            Several cities . . . drove them out as incendiaries.
                                                  --Bentley.

Incendiary \In*cen"di*a*ry\, a. [L. incendiarius, fr. incendium
   a fire, conflagration: cf. F. incendiaire. See {Incense} to
   inflame.]
   1. Of or pertaining to incendiarism, or the malicious burning
      of valuable property; as, incendiary material; as
      incendiary crime.

   2. Tending to excite or inflame factions, sedition, or
      quarrel; inflammatory; seditious. --Paley.

   {Incendiary shell}, a bombshell. See {Carcass}, 4.

Source : WordNet®

incendiary
     adj 1: involving deliberate burning of property; "an incendiary
            fire"
     2: arousing to action or rebellion [syn: {incitive}, {inflammatory},
         {instigative}, {rabble-rousing}, {seditious}]
     3: capable of catching fire spontaneously or causing fires or
        burning readily; "an incendiary agent"; "incendiary bombs"

incendiary
     n 1: a criminal who illegally sets fire to property [syn: {arsonist},
           {firebug}]
     2: a bomb that is designed to start fires; are most effective
        against flammable targets (such as fuel) [syn: {incendiary
        bomb}, {firebomb}]